The Clinical Oncology Program is the intramural treatment-research arm of the National Cancer Institute. In recognition of the assignment of acquired immune deficiency disease (AIDS) as the number one priority of the DHHS, a number of research projects within the laboratory of the Office of the Associate Director have been distantly related pathogenic human retroviruses broadly grouped into what is called the HTLV family of viruses. HTLV-III (also called LAV) is the etiologic agent of AIDS and the studies in the OAD are exploring new strategies for pharmacologic interventions against the etiologic pathogen of this disease. These studies are also exploring how viruses inthe HTLV-family can perturb immune reactions even in settings where they do actually destroy cells with immune potential. During the past year the OAD has focused on the development of anti-viral agents and the implementation of such agents in clinical trials. We have conducted a feasibility study using one such agent - suramin - to see if it is possible to suppress the replication of HTLV-II in vivo. Suramin was selected because it had been shown to inhibit the reverse transciptase of animal retroviruses in 1979, and because it had been used in human beings (for a totally different reason) for many decades, thus obviating the need for preclinical testing. This approach may provide a model for studying other agents.